Is Lane Splitting Legal in California?


In the United States, the federal government does not regulate traffic practices like lane splitting.

Instead, this is handled by each individual state, meaning that lane splitting may be legal in one state but not another.

Therefore, if you want to know if lane splitting is legal in California, you have to look at the relevant state laws.

So, Is It Legal in California?

Yes, actually. California is the only state in the US that expressly allows lane splitting. This has been the case since the California Assembly passed Bill 51 (AB 51) in August 2016. 

Prior to the bill’s passage, lane splitting was de facto allowed by the California Highway Patrol, but it remained in a legal gray area leading to confusion among motorcyclists and drivers alike.

Under the new law, the Highway Patrol was able to develop guidelines for safe lane splitting and resolving disputes. 

Guidelines for Lane Splitting Safely in California

AB 51 allowed the California Highway of Patrol to

“develop educational guidelines relating to lane splitting in a manner that would ensure the safety of the motorcyclist and the drivers and passengers of the surrounding vehicles.”


To do this, they were instructed to consult with other organizations like the Department of Motor Vehicles.  

The current guidelines can be found on the California Highway Patrol’s website and include:

  • Consider the total environment when you are lane splitting (this includes the width of lanes, the size of surrounding vehicles, as well as current roadway, weather, and lighting conditions).
  • Danger increases at higher speed differentials.
  • Danger increases as overall speed increases.
  • It is typically safer to split between the far left lanes than between the other lanes of traffic. 
  • Avoid lane splitting next to large vehicles (big rigs, buses, motorhomes, etc.).
  • Riding on the shoulder is illegal; it is not considered lane splitting.
  • Be visible – Avoid remaining in the blind spots of other vehicles or lingering between vehicles.
  • Help drivers see you by wearing brightly colored/reflective protective gear and using high beams during daylight.

Additionally, the CHP lays out guidelines for the drivers of other vehicles.

These instruct them on how to drive in a way that facilitates lane-splitting without endangering motorcyclists.

They include:

  • Lane splitting by motorcyclists is legal in California.
  • Intentionally blocking or impeding a motorcyclist in a way that could cause harm to the rider is illegal. 
  • Opening a vehicle door to impede a motorcyclist is illegal.
  • Drivers in the far left lane should move to the left of their lane to give motorcyclists ample room to pass.

Why Did California Legalize Lane Splitting?

While lane splitting was in a kind of gray area before AB 51, the government decided to expressly legalize lane splitting after a study conducted in 2015 by the University of California.

Improved Safety

Berkeley’s Safe Transportation Research and Education Center found that the practice is safe in traffic moving at 50 mph or less and when the motorcyclist doesn’t go faster than the surrounding vehicles by more than 15 mph.

Plus, the study found that motorcyclists who practiced lane-splitting usually rode during commuting hours, used better helmets, drove more slowly, and were unlikely to drink alcohol and ride.

Improved Traffic Congestion

motorcycle in traffic congestion

On top of that, California has more people and higher traffic volume than other states, something that lane splitting can help alleviate.

If motorcyclists can’t lane split, they must take up the same space on the freeway as a car, leading to more congestion.

By expressly legalizing lane splitting, California aimed to relieve some of the traffic congestion on their many freeways used for commuting.  

Is Lane Splitting Safe in California?

As the UC Berkeley study found, lane splitting is, in principle, safe in California. The main problem tends to be other drivers who are confused about or unaware of the laws regarding lane splitting. 

This was a large part of why California passed AB 51, allowing for the creation of guidelines to clear things up. Nevertheless, some motorists remain ignorant of the new law and may try to impede motorcyclists they believe are illegally lane splitting or trying to cut ahead in traffic.

Safety First

This is why it is imperative to follow the guidelines on safe lane splitting and wear the appropriate safety gear. Additionally, practice good situational awareness and defensive driving. Do not assume all other motorists will necessarily facilitate your lane splitting as they should. 

By adhering to these essential safety practices you can not only lane split legally in California and reduce traffic congestion and your commute time, but you can also lane split safely and reduce your chances of an accident.